My contribution both as engineer and researcher is to understand the middle ground between man and nature. Flood defences protect us from the water but are also integrated with many other functions such as housing and nature. Depending on the location, some functions are more common than other ones (see photo). This shared-use of the flood defences often comes with conservative estimates for a robust design that guarantees the flood safety. While having multi-functional flood defences generally impose restrictions on the design, some elements in the natural foreshores or flooded areas near the dike can contribute to reducing flood risk. For example, vegetated foreshores in coastal areas can damp the amount of wave energy that reaches the dikes. Aside from natural values, coastal salt marshes can also capture clay over time which may be used in future dike reinforcements. With the new probabilistic risk approach recently adopted in the Netherlands, we may be able to quantify the effects on flood safety of both standard and nature-based reinforcement measures. Yet, an integrated risk assessment framework is required.
The objective of my research project is to gain more insight into the shared-use of flood defences on flood risk reduction. I do so by using the new probabilistic risk approach to determine the safety level of flood defences that are shared with traditional functions such as housing. I further assess the effects on flood safety of some nature-based measures applied in innovative dike reinforcements.